�鶹��Ժ

A CU-Boulder astrophysicist who aims to probe the origins of the universe from the far side of the moon has been elected vice president of the American Astronomical Society, the group has announced.

Jack O. Burns, a University of Colorado Boulder professor of astrophysical and planetary sciences, is one of three vice presidents of the AAS. The AAS is described as the premiere organization of professional astronomers in North America and perhaps the world.

The organization’s scientific and educational programs are among the “most important presented anywhere,” Burns said.

As vice president, Burns will be responsible for assembling scientific programs that are broad, diverse, touch on the forefront of science and include educational innovations, he said.

Burns is an expert in public policy and science policy as they relate to space. At CU-Boulder, he teaches classes on space policy, an area he has a particular passion for. “We live and die by the funding available,” he observed.

NASA is arguably the most popular federal program and has been since Sputnik’s day.

But helping the AAS membership become more familiar with the congressional appropriations process is important, Burns said. “I want to be sure that area is well covered.”

Additionally, Burns hopes to further diversify the program, to feature more talks by junior members of the society, women and ethnic minorities. While astronomy and astrophysics attract and retain more women and ethnic minorities than fields such as physics, there’s still progress to be made, Burns said.

CU-Boulder has the largest undergraduate majors program in astrophysics and astronomy in the country. Women make up nearly 50 percent of undergraduates. But they are not as well represented in the senior ranks. “Hopefully, over time, that will happen.”

Those who ask Burns why astronomy and astrophysics have such broad appeal are likely to get an enthusiastic reply along these lines: Black holes! Exoplanets! What’s better than studying them?

“It’s just the kind of thing that catches people’s attention, whether you’re talking about women or men,” Burns said, adding, “It’s not that astrophysics is any easier than physics; it’s not.”

Burns is director and principal investigator of the Lunar University Network for Astrophysics Research, a consortium of research institutions conducting research, education, outreach and community development to advance science from the moon.

The moon is described as a unique platform for fundamental astrophysical measurements of gravitation, the sun and universe.

Lunar Laser Ranging of the Earth-Moon distance provides extremely high-precision constraints on general relativity, alternative models of gravity, and the present state of the core of the moon, the LUNAR web site states.

A radio telescope on the far side of the moon will be an unparalleled “heliospheric and astrophysical observatory,” since the moon lacks a permanent ionosphere and is shielded from Earth’s radio emissions.

That project is designed to focus partly on the “dark ages” of the universe. Burns explains this as a gap in the cosmological record. About 13.7 billion years ago, the universe began with a very Big Bang. Some 400,000 years later, electrons and protons merged to form atoms, and that cleared the “cosmic fog,” permitting our first glimpse of the early universe. Radio telescopes detect this as the “cosmic microwave background,” a faint signal from all directions.

About a half billion years later, the first stars and galaxies started to form. They emitted visible, ultraviolet and infrared light seen by powerful instruments like the Hubble Space Telescope and the James Webb Space Telescope, scheduled to launch in 2018. The problem is that there’s a half-billion-year gap between the cosmic microwave background and when we first see stars.

“What happened during that time period? We have no way of knowing that.”

Those half-billion years are called the “dark ages” because there is no visible light. There is hydrogen, which is emitting radiation in the microwave part of the electromagnetic spectrum. But the sources of these emissions are so far back in time, they are “redshifted,” meaning that their wavelengths are “shifted” toward the red, or longer, part of the spectrum.

This redshift results from the expansion of the universe, stretching the fabric of spacetime, the distances between galaxies, even the wavelength of light.

Redshifted microwaves from the “dark ages” can’t be seen with regular telescopes, or even with radio telescopes on Earth.

That part of the radio spectrum is too polluted on Earth, Burns notes. Garage-door openers, satellite transmissions from Digital TV, even the ionosphere (the uppermost part of the atmosphere) produce radio noise that completely overwhelms any weak signal from 13 billion years back.

One place that’s truly “radio quiet,” however, is the far side of the moon, which always faces away from the Earth. Putting radio telescopes there, as Burns’ project would do, would allow scientists to detect these weak signals. “Scientifically, it’s very exciting, very fundamental.”